Animation is a big task, often involving repetitive work. This is why many different techniques have been developed over the years, to hasten, and reduce the workload facing animators.
To manage all these features, Blender has three Animation editors (three window types):
- The Ipo Curve editor
- This is the lowest-level editor, where you use one curve to control each animated property/setting.
- The Action editor
- This editor is somewhat similar to the Ipo one – it gives a less-precise, more general view of an object’s animation Unlike the IPO editor, it allows multiple bones/objects to be edited in the same instance.
- The NLA editor
- The idea behind this high-level editor is borrowed from the non-linear video editors: each element represents an action, which you can move, duplicate, shrink/pull (i.e. fasten/slow down), etc., to your liking. If IPO keys are like mesh faces, an 'NLA action' is an object encapsulating those mesh faces, with a modifier.
- Ipo curves...
- ...are used by actions...
- ...which are used by the NLA.